New compounds of the benzanthraquinone series



' pounds of the benzanthraquinone Patented May 12, 1931 p unmet s'r RUDOLF M. HEIDENREICH, or ELBER-FELD, GERMANY,ASSIG1\TOR"1O GENERAL ANILINE wonxs'ina, or new YORK, N. Y., A conroanrton or DELAWARE NEW COMPOUNDS OF BENZANTHRAQUINONE SERIES Ito Drawing. Application filed ember 15,1927, Serial No. 226,528, and in Germany October a, 1926. p

The present invention relates to newcomseries and to a process of preparing same. Moreparticul'a'rly it relates to the compounds of the general formula:

wherein X stands for thecarboxylic acid group, or both Xs jointlystand for vthe group: p p

andwhereinthe nucleus marlred I may be substituted by halogen atoms.

p I have found that the naphthalic-acidlbenzoyl-ortho-carboxylic acid, which has been described by Graebe in 'Annalen der Chemie vol. 327 p. 101, and the derivatives thereof, are converted by heating with acid condensing agents such as sulfuric acid, aluminium chloride, etc. into new compounds of the benzanthraquinone-series. I prefer to carry out this process by heating the naphthalic acid compounds to a temperature of about l70200 C.'in the presence of concentrated sulfuric acid with or without the addition of boric acid. The reaction takes place e. g. according to the following equationf The anhydr'ide thus obtainedcan be easily proven when the red color of the vat which results by adding caustic soda solution and hydro sulfite to a test portion remains un- V changed. Generally the reaction is completed after about twenty minutes. The melt is poured into water and the 1.2-benzanthraquinone-peri-dicarboxylic acid thereby pre cipitated is washed with water. On re-crystallizing from a large amountofni-tro-benzene or ortho-dichloro-benzene the anhydride is obtained in beautiful golden yellow needles, which dissolve in sulfuric acid with a reddishyellow color, in alkali with a yellow color and melt above 300 C. Therree peri-d'icarbox'ylic'acid be precipitated with acid from the alkaline solution of the anhydride at'room temperature, on heating the same, it is again transformed into its, anhydrider B emen, thraquinone-peri-dicarboxylic acid yields with alkali and hydrostalfite a beautifulred vat from which the acid is recovered by'blo'wing air through the solution. The new product is presumed to possess the following formula:

H000 coon Example Acenaphthene is suspended in carbon disulphide and condensed with the anhydride of 3.6-dichloro-phthalic by means of anhydrous aluminium chloride, whereby acenaphthoyl 5-3-6-dichloro-phenyl-ortho-carboxylic acid is obtained (white needles from chlorobenzene, melting at 239 5 C. uncorr.). Oxidation with sodium bichromate causes, conversion into naphthalic acid anhydride 4L benzoyl- 3 -6-dichloro-ortl 1obenzoic acid, (white needles from glacial acetic acid, melting at27 l C. uncorr.). When the latter is heated for about twenty minutes in concentrated sulfuric acid according to the process described in Example 1, the anhydride of l.2-benzanthraquinone-5.S-dichloro-peri-dicarboxylic acid is obtained, (yellow needles from nitrobenzene). The new compound is presumed to possess the following formula 1100(1) CODE In the same way e. g. from 1.8-naphthalimid-4-benzoyl-ortho-carboxylic acid the 5.6- benzanthraquinone-peri-dicarboxylic a ci d imide having most probably the formula:

NH (.40 do product results having most probably the following formula:

I claim v 1. As new products the compounds of the general formula:

wherein X stands for the carboxylic acid group, or both Xs jointly stand for the group,

o l o oo and wherein the nucleus marked I may be sub stituted by halogen atoms.

2. As a new product the compound of the formula:

HOOC COOH which crystallizes in the form of its anhydride in beautiful golden-yellow needles, dissolving in strong sulfuric acid with a reddishyellow color and melting above 800 C.

3. A process for the manufacture of new compounds of the benzanthraquinone series which consists in heating to an elevated temperature in the presence of an acid condensing agent a compound of the general formula wherein X stands for the carboxylic acid group, or both Xs jointly stand for the group:

and wherein the nucleus marked I may be substituted by halogen atoms.

4. A process for producing a new compound of the benzanthraquinone series which consists in heating naphthalic-acid-4i-benzoylortho-carboxylic-acid to about 17 0200 C. in the presence of concentrated sulfuric acid.

In testimony whereof I have hereunto set my hand.

RUDOLF M. HEIDENREICH.

Certificate of Correction Granted May 12, 1931, to

RUDOLF M. HEIDENREIOH It is hereby certified that error appears in the printed specification of the abovenumbered patent requirlng correction as follows: Page 2, claim 3, after line 105,

insert the following formula:

Patent No. 1,804,870.

V I Same page after line insert the iolloxyingformnlaz I i 00K o v and that the said Letters Patent should he read With these corrections therein that the same may conform to the record of the case in the Patent Office.

, Signed and sealed this 21st day of July, A. D. 1931.

[S-EAL] M. J. MOORE,

Acting Commissioner 0 f Patents. 

